books.google.com - This classic study notes the first appearance of a mathematical symbol and its origin, the competition it encountered, its spread among writers in different countries, its rise to popularity, its eventual decline or ultimate survival. The author's coverage of obsolete notations — and what we can learn...http://books.google.com/books/about/A_History_of_Mathematical_Notations.html?id=7juWmvQSTvwC&utm_source=gb-gplus-shareA History of Mathematical Notations